| Message ID | 20250219162131.416719-3-zohar@linux.ibm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | ima: limit both open-writers and ToMToU violations | expand |
On 2/19/25 11:21 AM, Mimi Zohar wrote: > Each time a file in policy, that is already opened for read, is opened > for write a Time-of-Measure-Time-of-Use (ToMToU) integrity violation > audit message is emitted and a violation record is added to the IMA > measurement list, even if a ToMToU violation has already been recorded. > > Limit the number of ToMToU integrity violations for an existing file > open for read. > > Note: The IMA_MUST_MEASURE atomic flag must be set from the reader side > based on policy. This may result in a per open reader additional ToMToU > violation. > > Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Tested-by: Stefan Berger <stefanb@linux.ibm.com> > --- > security/integrity/ima/ima_main.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c > index cde3ae55d654..f1671799a11b 100644 > --- a/security/integrity/ima/ima_main.c > +++ b/security/integrity/ima/ima_main.c > @@ -129,9 +129,10 @@ static void ima_rdwr_violation_check(struct file *file, > if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) { > if (!iint) > iint = ima_iint_find(inode); > + > /* IMA_MEASURE is set from reader side */ > - if (iint && test_bit(IMA_MUST_MEASURE, > - &iint->atomic_flags)) > + if (iint && test_and_clear_bit(IMA_MUST_MEASURE, > + &iint->atomic_flags)) > send_tomtou = true; > } > } else {
Hi Mimi,
LGTM.
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Kind regards,
Petr
Hi Mimi,
Tested-by: Petr Vorel <pvorel@suse.cz>
Kind regards,
Petr
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index cde3ae55d654..f1671799a11b 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -129,9 +129,10 @@ static void ima_rdwr_violation_check(struct file *file, if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) { if (!iint) iint = ima_iint_find(inode); + /* IMA_MEASURE is set from reader side */ - if (iint && test_bit(IMA_MUST_MEASURE, - &iint->atomic_flags)) + if (iint && test_and_clear_bit(IMA_MUST_MEASURE, + &iint->atomic_flags)) send_tomtou = true; } } else {
Each time a file in policy, that is already opened for read, is opened for write a Time-of-Measure-Time-of-Use (ToMToU) integrity violation audit message is emitted and a violation record is added to the IMA measurement list, even if a ToMToU violation has already been recorded. Limit the number of ToMToU integrity violations for an existing file open for read. Note: The IMA_MUST_MEASURE atomic flag must be set from the reader side based on policy. This may result in a per open reader additional ToMToU violation. Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> --- security/integrity/ima/ima_main.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)